Terminal grain dryer



Feb. 8, 1966 B. L. TOMLINSON TERMINAL GRAIN DRYER Filed March 30, 1961INVENTOR. 851v L. TOML/NSON United States Patent C) 3,233,337 TERMINALGRAIN DRYER Ben L. Tomlinson, Hopkins, Minn., assignor, by mesneassignments, to Hart-Carter Company, Chicago, 111., a corporation ofDelaware Filed Mar. 30, 1961, Ser. No. 99,489 Claims. (Cl. 34--65) Thisinvention relates to grain dryers. More particularly, it relates tograin dryers of the type designed for use at grain terminals to drygrain continuously and rapidly in large capacities in order to handlethe large volumes of grain which must be accommodated by grainterminals.

Various types of terminal grain dryers have been designed previously inan effort to provide a dryer having adequate capacity and satisfactorilyperforming the necessary drying function at a grain terminal. To thebest of my knowledge none of these have been satisfactory for a numberof reasons. It has always been difficult to obtain a terminal dryerhaving adequate capacity which will perform the necessary dryingfunction in a satisfactory manner. In addition, most such dryers requirestructure which cover relatively large areas and since realty adjacentgrain terminals is generally held at a premium price, such grain dryersprove very costly to maintain and operate. Many of these grain dryersattempt to recirculate the air with the consequent result, of course,that the drying function suffers. Many of these devices do not heatevenly throughout and there is a very substantial heat loss in most ofthem because they require considerable duct work in order to transferthe heat from its source to the point of application. One of the mostserious drawbacks of grain dryers known is their very distinct danger offire for in these dryers dust tends to collect and soon constitutes avery substantial fire hazard In recent years the grain which is reachingthe grain terminals has become increasingly less clean in that modernlarge scale harvesting methods frequently results in the harvested grainhaving increasingly larger proportions of dust, dirt, debris, etc. Manyof such grain dryers, in an etfort to obtain the desired capacity havereached almost prohibitive heights with consequent increase in cost ofmanufacture, assembly, etc. Most such grain dryers have blind spots inwhich dust, chaff, etc. collect and which are inaccessible for cleaning,thus constituting a very real fire hazard. My invention is directedtoward overcoming these disadvantages and I have found that my terminalgrain dryer functions in a highly improved manner over any grain dryerheretofore known.

It is a general object of my invention to provide a novel and improvedterminal grain dryer of relatively simple and inexpensive constructionand improved efiiciency.

A more specific object is to provide a novel and improved terminal graindryer having much greater capacity than heretofore known and constructedand arranged to substantially reduce fire hazards.

Another object is to provide a novel and improved terminal grain dryerwhich will heat evenly throughout the drying area.

Another object is to provide a novel and improved terminal grain dryerin which all of the air which is heated is forced to pass through thegrain being dried within the dryer.

Another object is to provide a novel and improved terminal grain dryerwhich eliminates blind spots in which dirt, chaff, etc. may collect ininaccessible areas with consequent increased fire hazards.

Another object is to provide a novel and improved terminal grain dryerconstructed and arranged to facilitate maintenance and servicing of thedryer after it has been placed in operation and to simplify the entirestructure 3,233,337 Patented Feb. 8, 1966 I for maintenance, inspection,observation, and repair while yielding an increased capacity, improvedfunction and substantial reduction in fire hazards.

Another object is to provide a novel and improved grain dryer which canbe constructed upon a minimum area without extending to prohibitiveheights while providing an increased capacity over other dryersheretofore known when mounted upon a given restricted ground area.

These and other objects and advantages of my invention will more fullyappear from the following description, made in connection with theaccompanying drawings, wherein like reference characters refer to thesame or similar parts throughout the several views, and in which:

FIG. 1 is a side elevational view of one embodiment of my invention withthe upper portion thereof shown in vertical section and portions brokenaway to show the heat generating apparatus in elevation.

FIG. 2 is a perspective view of the divider cover member carried by theinner wall structure of my dryer at the upper end thereof to uniformlydivide the grain between the four sides of the dryer.

FIG. 3 is a horizontal sectional view taken along approximately line 33of FIG. 1.

FIG. 4 is a fragmentary detailed vertical sectional view on an enlargedscale through the discharge and conveying portion of one of the sides ofmy dryer; and

FIG. 5 is a horizontal sectional view taken along line 5 5 of FIG. 1.

One embodiment of my invention, as shown in FIGS. 1-5, includes anupright shaft indicated generally by the numeral 6 and defined by aplurality of perforated inner walls 7, 8, 9, and it). As best shown inFIGS. 1 and 3 these walls are arranged to define an open interiorindicated by the numeral 11 which is rectangular in horizontal sectionas clearly shown in FIG. 3. The vertical walls 710 inclusive areenclosed by a second set of vertical walls which are also perforated.These outer walls 12, 13, 14, and 15 are spaced outwardly from the innerwalls and are each disposed parallel to one of the inner walls so as toenclose the inner walls and defining an area which is also rectangularin horizontal section. Reference to FIG. 3 shows that these perforatedouter walls 1215 are spaced outwardly from the inner walls andcooperatively define a four-sided grain drying column indicated in FIG.4 by the numeral 17. Vertically extending panels 18 serve to connect theassociated inner and outer walls and divide each side of the dryingcolumn into a plurality of separate vertical chutes through which thegrain descends.

The weight of the upright shaft 6 is supported by a plurality of posts1% which are angled in cross-section and supported by footings 20. Theseangled posts 19 are connected to the inner and outer walls at each ofthe corners as best shown in FIG. 3.

Secured to the upper ends of each of the inner walls 8-10 inclusive is adivider member indicated generally by the numeral 21. This dividermember 21 is comprised of a hood or cover the upper portions 22 of whichare truly conical in configuration. This cover member 21 has a pluralityof vertically extending side walls such as is indicated by the numeral23 and each extends in the vertical plane of its associated perforatedinner wall and is fixedly connected thereto. The upper edge 24 of eachof the vertically extending walls 23 is arcuately shaped and connectedalong its length to the conical portion 22 of the divider member so thatwhen grain is deposited from directly above upon the apex 25 of thedivider 21, the grain will be evenly divided and distributed to each ofthe four sides of the drying column 17 in such a manner that the fineswill not be separated from the heavies. In other words, by utilizing adivider member constructed as shown herein I have eliminated a normaltendency of the heavies to collect in areas where there is the greatestangle of inclination and the lights to collect in the areas of lesserinclination with the consequent adverse effect. of unequal drying andloss of the heat and pressure.

A roof member 26 covers the entire shaft and is secured, as best shownin FIG. 1, to the outer walls of the structure. A grain chute 37 isconnected to the apex of the roof 26 directly above the apex 25 of thedivider member 21 and deposits grain as needed upon the'divider member.The capacity of the area surrounding the divide 21 is ap proximately 350bushels.

Mounted within the open interior 11 of the shaft 6 is a firing tube 28which, as shown in FIG. 1, is directed upwardly. It will be noted thatthe entire firing tube 28 is disposed within the vertical confines ofthe inner wall members 7-10 inclusive and that its open upper end isdirected upwardly so that the hot air emanating therefrom will bedischarged in an upward direction. A burner 29 is mounted directly belowthe firing tube 28 and within the lower end portions thereof, thisburner also being directed upwardly so that the heat generated therebywill move upwardly through the firing tube and be discharged through theopen upper end. A blower 3% is mounted in the open upper end of thefiring tube 28 to draw the hot air upwardly through the tube anddischarge it under pressure into theopen interior 11 of the shaft. Thisblower 30 is driven by an electrical motor 31 which is surrounded by aconduit 32 extending downwardly within the firing tube and thenoutwardly through an opening 33 formed in the wall of the firing tube.

Surrounding the firing tube 28 is a separator panel 34 which extendsoutwardly and downwardly from the firing tube with its lower peripheralportions being disposed immediately adjacent to but slightly spaced fromthe inner surfaces of the side walls 7, 8, 9, and 10. This separator 34separates the interior 11 of the shaft 6 into an upper hot air chamber35 and a lower cool air chamber as. A man hole opening 37 is formedthrough the panel 34 and a cover member 38 is hinged immediately belowthe opening to permit the same to swing between a position covering theopening and a second position at which it hangs downwardly from thehinge to permit a service man to pass upwardly through the opening.

The lower end of the cool air chamber 36 is substantially closed otf bya closure panel 39 which surrounds the firing tube 28 and extendsdownwardly and outwardly therefrom as best shown in FIG. 1 with itslower peripheral portions immediately adjacent the lower ends of theinner walls 7, 8, 9, and 19 but in slightly spaced relation thereto, asbest shown in FIG. 4-7 A cool air fan 40 is mounted beneath the walls ofthe closure panel 39 and is directed upwardly to throw the cool airthrough an opening 41 formed therein. An electric motor 42 drives theblower 40 which draws the cool air from beneath the shaft 6, as bestseen in FIG. 1. A man hole opening 43 and a cover member 44 therefor isalso provided for the 010- sure panel 39 to enable a service man toclimb upwardly into the interior of the cool air chamber 36 forservicing and repairing the blower 4'9 or into the hot air chamber (viathe man hole opening 3'7) to service or repair the blower 30 as desired.To this end a ladder 45 is mounted on the exterior of the firing tube30.

At each side of the shaft 6 directly below the column of grain 17 is anelongated panel 46 which, as best shown in FIG. 4, has its upper edgeportions fixedly secured to the peripheral portions of the closure panel33 The panel 46 is vertically spaced from the lower edge of the innerwalls such as the wall 7 and extends outwardly with its lower portionsdisposed in vertically spaced relation to the lower ends of the outerwalls such as the wall 12. Thus, as shown in FIG. 4, the panels 46cooperatively define a chute 47 in cooperation with the associated innerand outer walls and a hinged cover member 48 which is carried by thelower end of the outer side wall such as 12. Thus, the column of grain17 as it moves downwardly between the inner and outer wall will bedirected outwardly against a variable speed rotary feed control 49. Asshown this feed control 49 is comprised of a shaft 50 and a plurality ofradially outwardly extending vanes 51 mounted thereon: and rotatingtherewith about the longitudinal axis of the shaft. The shaft 50 extendsacross the entire width of its associated side of the drying structureand is driven, in a. manner which will be hereinafter described, torotate in the direction indicated by the arrow in FIG. 4.

Carried by the lower end portions of the panel 46 in receiving relationthereto is a trough member 52 which, like the shaft 50, extends alongthe full width of its associated side of the drying structure. It willbe understood that each side of the structure is provided with a similarpanel 46, control means 49 and trough 52 as well as an anger conveyor 53one each of which is mounted within each of the troughs 52. The augerconveyors 53 move the grain longitudinally of the trough 52 to adischarge 54 as shown in FIG. 1.

The auger conveyors 53 vary in size as best seen in FIG. 3. Theconveyors at the top and at the left hand side of FIG. 3 are six inchconveyors while the conveyor at the right hand side is a nine inchconveyor and the conveyor at the lower side of the drawing is a twelveinch conveyor. The conveyors, as best shown in FIG. 1, are disposed atdifferent elevations so that the six inch conveyor at the left hand sideof FIG. 3 will move the grain therein in the direction of the arrow andempty from above into the twelve inch conveyor shown at the lowerportion of that figure. The twelve inch conveyor moves the material inthe direction of the arrow to the discharge 5% which is disposed at thelower right hand corner of FIG. 3. The six inch conveyor shown at thetop of FIG. 3 moves the grain in the direction by the arrow to the rightand discharges from above into thenine inch conveyor which in turn movesthe grain in the direction of the arrow toward the discharge at thelower right hand corner of FIG. 3. The twelve inch conveyor is driven byan electric motor 55 and a belt 56. The nine inch conveyor is driven byan electric motor 57 and a belt 58. A chain 59 drives the six inchconveyor, as shown at the upper right hand corner of FIG. 3, the chainin turn being driven by the shaft and pulley arrangement connected tothe shaft of the nine inch conveyor. The six inch conveyor shown at thetop of FIG. 3 in turn drives the six inch conveyor at the left hand sideof that figure by means of gearing which is not shown.

Each of the feed controls 49 are connected together at their ends bymeans of gearing 60 which is best shown in FIG. 5 so that one drives theother, each at the same rate of speed. The power is supplied by a motor6i. which is mounted below the closure panel 39 and is connected indriving relation, as best shown in FIG. 5, by means of a chain 62 to oneof the shafts 50 of one of the feed controls 49, the chain 62 passingthrough one of the plates 19 through a slot provided for that purpose.Means for varying the speed (not shown) is provided so that the rate ofrotation of the feed controls 4! may be, controlled and hence the rateof descent of the grain. column 17 may be varied in accordance with thedrying; requirements. 7

The operation of my terminal grain dryer is initiated by controls (notshown), these controls being arranged so that the blower 3t commences abrief period before the blower 4%? is started. This causes pressure tobe built up initially within the hot air chamber 35 and force any dust,etc. which may have collected in the hot air chamber downwardly into thecool air chamber 36 through the slight space provided between the lowerperipheral portions of the panel 34 and the inner walls of the dryer.Thus each time the drying operation commences the hot air chamber 35 isemptied of the material which normally creates serious fire hazards andis transferred to the cool air chamber where such fire hazards aregreatly reduced.

During the grain drying operation, the grain being considerably heavierthan the dust (which is indicated by the numeral 63), the grain extendsfrom the lower end of the wall 7 across to the panel 46 as seen in FIG.4. Most of the dust 63 is transferred back into the grain during thedrying operation at this point for it is absorbed into the fiow ofgrain. Thus it can be seen that may dryer is constructed so as tocontinuously reduce and remove fire hazards during the actual dryingoperation and to permit further substantial reduction of the firehazards when the drying operation is not in progress.

After the blower 30 has created pressure within the drying chamber 35,the blower 40 is also actuated to create an internal pressure within thecool air chamber 36. Thus hot dry air is forced outwardly through thegrain held between the perforated inner walls and the perforated outerwalls with the result that the moisture is Withdrawn from the grain asit descends between these Walls and is carried outwardly with the hotdry air. The temperature of the grain is increased substantially whiledescending from the top of the shaft to an elevation opposite the coolair chamber 36. While passing downwardly between the inner and outerwall opposite the cool air chamber 36, cool air is forced outwardlythrough the perforated inner and outer walls and through the graincolumn to effectively cool the same and complete the drying operation.As pointed out above, the rate of descent of the grain column 17 iscontrolled by varying the rate of rotation of the control members 49.

It should be noted that I have completely eliminated the normal tendencyof grain in dryers of this type to rearrange itself in such a mannerthat the lighter kernels or lights collect in one portion of the dryerwhile the heavier kernels or heavies collect in another portion. Such asituation causes uneven drying and an inefiicient operation in additionto increasing fire hazards for the lights dry quickly and, whensubjected to the necessary heating required to dry the heavies, aserious fire hazard results. The grain deposited upon the conicalportion of the divider 21 completely eliminates this tendency so thatthe heavies and lights will remain mixed in their original proportionsand will be distributed between the four sides of the dryer evenly.

It should also be noted that the structure of my grain dryer while beingextremely simple lends itself to a highly efiicient operation. Moreover,this simplicity facilitates maintenance, inspection, observation, andrepair while giving increased capacity and reducing fire hazards.Maintenance and repair of the blowers is greatly simplified by the useof the two man holes 37 and 43 and the fire hazards are verysubstantially reduced through the spacing of the separator 34 and theinner walls and the closure 39 and the inner walls.

From the above it can be seen that my terminal grain dryer will heatevenly throughout while causing all of the air which has been heated tobe driven through the dryer and the grain itself. It will be noted thatthere is no exterior duct work required and consequently no heat lossthereby. Moreover, my terminal grain dryer can be erected upon a minimumof ground area and yet provides substantially increased capacity in thatgrain is being continuously dried at all four sides of the dryer. Itshould be noted that there is no recirculation of air involved in thedrying operation in that none of the air after having once been passedthrough the grain is subsequently again passed through the grain in afurther attempt to perform a drying function.

It should also be noted that my grain dryer, because of its uniquedesign, will provide the same capacity as other dryers while requiringsuperstructure of a lower height or, in the alternative, greatlyincreased capacity when utiliz- 6 ing superstructureof the same height.In addition, all of the heat generated by the burning of the fuel isapplied directly to the grain and is conserved and utilized so that thedryer will operate at maximum efiiciency.

It Will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the parts withoutdeparting from the scope of my invention which consists of the mattershown and described herein and set forth in the appended claims.

What is claimed is:

1. A non-recirculating directly-fired terminal grain dryer comprising anupright shaft having perforated inner wall structure rectangular inhorizontal section and defining an open interior and having perforatedouter wall structure spaced outwardly from said inner wall structure andalso rectangular in horizontal section and cooperatively defining withsaid inner wall structure a four sided grain drying column therebetween,said grain drying column discharging at the lower ends of said wallstructures, means for continuously filling said column with grain to bedried as it descends between said wall structures, separator meansextending transversely across the open interior of said inner wallstructure to prevent the free passage of air thereby and separating thesame into an upper hot air chamber and a lower cool air chamber, saidupper hot air chamber having means for substantially closing off itsupper end to prevent free escape of air therethrough, means disposedentirely within the vertical confines of said inner wall structure forheating air and introducing the same under pressure into said upper hotair chamber and forcing the same without recirculation outwardly throughsaid inner and outer Wall structures and through the column of grain tothe exterior of said shaft, said lower cool air chamber beingsubstantially closed off at its lower end to prevent the free escape ofair therethrough, means disposed entirely within the vertical confinesof said inner wall structure for creating pressure u-pon cool air andintroducing the same into said lower cool air chamber and forcing thesame without recirculation outwardly through said inner and outer wallstructures and through the column of grain therebetween to the exteriorof said shaft, said shaft having an open bottom and said .air heatingmeans being comprised of a burner extending upwardly from a point atsaid open bottom below and exterior of said cool air chamber into afiring tube mounted within said inner wall structure and extendingupwardly through said cooler air chamber and into said upper hot airchamber and discharging into the latter, a blower directed upwardly anddisposed within the discharge of said firing tube, a motor connected tosaid blower and driving the same, and conduit means extending round saidmotor from said cooler air chamber to a point adjacent said fan andintroducing cool air from said cooler air chamber into said firing tubearound said motor.

2. A non-recirculating directly-fired terminal grain dryer comprising anupright shaft having perforated inner wall structure rectangular inhorizontal section and defining an open interior and having perforatedouter wall structure spaced outwardly from said inner wall structure andalso rectangular in horizontal section and cooperatively defining withsaid inner wall structure a four sided grain drying column therebetween,said grain drying column discharging at the lower ends of said wallstructures, means for continuously filling said column with grain to bedried as it descends between said wall structures, separator meansextending transversely across the open interior of said inner wallstructure to prevent the free passage of air thereby and separating thesame into an upper hot air chamber and a lower cool air chamber, saidupper hot air chamber having means for substantially closing off itsupper end to prevent free escape of air therethrough, means disposedentirely within the vertical confines of said inner wall structure forheating air and introducing the same under pressure into said upper hotair chamber and forcing the same without recirculation outwardly throughsaid inner and outer wall structures and through the column of grain tothe exterior of said shaft, said lower cool air chamber beingsubstantially closed off at its lower end to prevent the free escape ofair therethrough, means disposed entirely within the vertical confinesof said inner wall structure for creating pressure upon cool air andintroducing the same into said lower cool air chamber and forcing thesame without recirculation outwardly through said inner and outer wallstructures and through the column of grain therebetween to the exteriorof said shaft, said shaft having an open bottom and said air heatingmeans being comprised of .a burner extending upwardly from a point atsaid open bottom below and exterior of said cool air chamber into afiring tube mounted within said inner wall structure and extendingupwardly through said cooler air chamber and into said upper hot airchamber and discharging into the latter, a blower directed upwardly anddisposed within the discharge of said firing tube, a motor connected tosaid blower and driving the same, conduit means extending around saidmotor from said cooler air chamber to a point adjacent said fan andintroducing cool air from said cooler air chamber into said firing t-ubearound said motor, the lower end of said lower cool air chamber alsohaving a closable opening formed therethrough adapted to enable a man topass therethrough, and ladder means mounted on the exterior surface ofsaid firing tube and extending between the opening in said lower end andsaid separator means.

3. A non-recirculating directly-fired terminal grain dryer comprising:

(a) an upright shaft having an upper hot air chamber and a lower coolair chamber and having perforated inner wall structure rectangular inhorizontal section and defining an open interior and having perforatedouter wall structure spaced outwardly from said inner wall structure andalso rectangular in horizontal section and cooperatively defining withsaid inner wall structure a four sided grain drying column therebetween,said grain drying column discharging at the lower ends of said wallstructures,

(b) divider means connected to the upper end of said inner wallstructures and closing off said upper hot air chamber and beingcomprised of a cover having a plurality of flat vertically extendingwalls one each of which is connected to the upper end of one side ofsaid inner wall structure and extends upwardly therefrom andsubstantially as a continuation thereof, each of said walls having aconvex upper edge and the remainder of said cover member being trulyconical in shape and connected to the upper edges of said walls andextending downwardly from its apex at the same angle of inclination inall directions to said vertically extending walls whereby grain whendeposited from above upon the apex of said cover member will flow insuch a manner so as to avoid separating the light and heavy particles inthe grain and will distribute the same in an evenly divided flow ofuniform composition into each of the four sides of said grain dryingcolumn,

() means for introducing grain into said shaft and depositing the samefrom above upon said divider means at its apex,

(d) separator means extending transversely across the open interior ofsaid inner wall structure to prevent the free passage of air thereby andseparating the same into said upper hot air chamber and said lower coolair chamber,

(e) said lower cool air chamber having means to substantially close offits lower end to prevent the free escape of air therefrom,

(f) means disposed entirely within the vertical confines of said innerwall structure for heating air and introducing the same under pressureinto said upper hot air chamber and forcing the same outwardly throughsaid inner and outer wall structures and adapted to pass such airthrough a column of grain to the exterior of said shaft,

(g) means disposed entirely within the vertical confines of said innerwall structure for creating pressure upon cool air and introducing thesame into said lower cool air chamber and forcing the same outwardlythrough said inner and outer wall structures and adapted to pass suchair through a column of grain therebetween to the exterior of saidshaft, and

(h) means for controlling the rate of flow of grain downwardly betweensaid wall structures.

4. A non-recirculating directly-fired terminal grain dryer comprising:

(a) an upright shaft having perforated inner wall structure rectangularin horizontal section and defining an open interior and havingperforated outer wall structure spaced outwardly from said inner wallstructure and also rectangular in horizontal section and cooperativelydefining with said inner Wall structure a four sided grain drying columntherebetween, said grain drying column discharging at the lower end ofsaid wall structures,

(b) means for continuously filling said column with grain to be dried asit descends between said wall structures,

(0) separator means extending transversely across the open interior ofsaid inner wall structure to prevent the free passage of air thereby andseparating the same into an upper hot air chamber and a lower cool airchamber, said upper hot air chamber being substantially closed olf atits lower end to prevent free escape of air therethrough,

(d) said separator means terminating slightly inwardly of said innerwall structure and providing a small passage therebetween to permit dustto pass therethrough directly from said upper hot air chamber into saidlower cool air chamber,

(e) means disposed entirely within the vertical confines of said innerwall structure for heating air and having a discharge introducing suchair under pressure into said upper hot air chamber and forcing the sameoutwardly through said inner and outer wall structures and through thecolumn of grain to the exterior of said shaft,

(f) panel means substantially closing off said lower cool air chamber atits lower end to prevent the free escape of air therefrom andterminating slightly inwardly of said inner wall structure to permitdust to pass therethrough into the flow of cool dried grain,

(g) means disposed entirely within the vertical confines of said innerwall structure for creating pressure upon cool air and introducing thesame into said lower cool air chamber and forcing the same outwardlythrough said inner and outer wall structures and through the column ofgrain therebetween to the exterior of said shaft,

(h) said shaft having an open bottom and said air heating means beingcomprised of a burner extending upwardly within said shaft and havingits air intake in direct air-flow communication with the freeatmosphere,

(i) a firing tube having an upper discharge end mounted within saidinner wall structure and surrounding the discharge of said air heatingmeans in air-receiving relation and extending upwardly through said coolair chamber and into said upper hot air chamber and discharging into thelatter,

(j) a blower directed upwardly and disposed within the said dischargeend of said firing tube,

(k) and a motor connected to said blower for driving the same.

dryer comprising:

(a) an upright shaft having perforated inner wall structure rectangularin horizontal section and defining an open interior and havingperforated outer wall structure spaced outwardly from said inner wallstructure and also rectangular in horizontal section and cooperativelydefining with said inner Wall structure a four sided grain drying columntherebetween, said grain drying column discharging at the lower ends ofsaid wall structures,

(b) means for continuously filling said column with grain to be dried asit descends between said wall structures,

(c) separator means extending transversely across the open interior ofsaid inner wall structure to prevent the free passage of air thereby andseparating the same into an upper hot air chamber and a lower cool airchamber, said upper hot air chamber being substantially closed oif atits upper end to prevent free escape of air therethrough,

(d) means disposed entirely within the vertical confines of said innerwall structure for heating air and introducing the same under pressureinto said upper hot air chamber and forcing all of the same outwardlythrough said inner and outer wall structures and adapted to pass suchair through a column of grain to the exterior of said shaft,

(e) said air heating means having an air inlet means connected in directair-flow communication with the free atmosphere so as to receive airtherefrom without being drawn through the said perforated inner andouter walls,

(f) said lower cool air chamber having means for substantially closingoff its lower end to prevent the free escape of air therethrough,

(g) means disposed entirely within the vertical confines of said innerwall structure for creating pressure upon cool air and introducing thesame into said lower cool air chamber and forcing the same outwardlythrough said inner and outer wall structures and adapted to pass suchair through a column of grain therebetween to the exterior of saidshaft, (h) said shaft having an open bottom and said air heating meansbeing comprised of a burner extending upwardly within said shaft withits air inlet means connected in direct air-flow communicating relationwith the free atmosphere through said open bottom.

References Cited by the Examiner UNITED STATES PATENTS 51,169 11/1865Gecmen 34174 865,546 9/1907 Uhlhorn 34--174 1,711,574 5/1929 Miller34--174X 2,227,634 1/1941 Dalin 34165 2,245,664 6/1941 Gronert 341742,602,498 7/1952 Overton 15912 2,627,670 2/1953 Hurst et al 34-1742,654,590 10/ 1953 Molenaar 34-65 2,706,345 4/1955 Arndt 34-1742,799,097 7/ 1957 Williams 34174 X 2,858,620 11/1958 Naylor 34174 X2,991,559 7/1961 Pierpoint 34-174 X 3,053,522 9/1962 Applegate 34174 X3,092,472 6/ 1963 Figley 34174 X FOREIGN PATENTS 529,901 1l/1940 GreatBritain.

WILLIAM F. ODEA, Acting Primary Examiner.

Examiners.

5. A NON-RECIRCULATING DIRECTLY-FIRED TERMINAL GRAIN DRYER COMPRISING:(A) AN UPRIGHT SHAFT HAVING PERFORATED INNER WALL STRUCTURE RECTANGULARIN HORIZONTAL SECTION AND DEFINING AN OPEN INTERIOR AND HAVINGPERFORATED OUTER WALL STRUCTURE SPACED OUTWARDLY FROM SAID INNER WALLSTRUCTURE AND ALSO RECTANGULAR IN HORIZONTAL SECTION AND COOPERATIVELYDEFINING WITH SAID INNER WALL STRUCTURE A FOUR SIDED GRAIN DRYING COLUMNTHEREBETWEEN, SAID GRAIN DRYING COLUMN DISCHARGING AT THE LOWER ENDS OFSAID WALL STRUCTURES, (B) MEANS FOR CONTINUOUSLY FILLING SAID COLUMNWITH GRAIN TO BE DRIED AS IT DESCENDS BETWEEN SAID WALL STRUCTURES, (C)SEPARATOR MEANS EXTENDING TRANSVERSELY ACROSS THE OEPN INTERIOR OF SAIDINNER WALL STRUCTURE TO PREVENT THE FREE PASSAGE OF AIR THEREBY ANDSEPARATING THE SAME INTO AN UPPER HOT AIR CHAMBER AND A LOWER COOL AIRCHAMBER, SAID UPPER HOT AIR CHAMBER BEING SUBSTANTIALLY CLOSED OFF ATITS UPPER END TO PREVENT FREE ESCAPE OF AIR THERETHROUGH, (D) MEANSDISPOSED ENTIRELY WITHIN THE VERTICAL CONFINES OF SAID INNER WALLSTRUCTURE FOR HEATING AIR AND INTRODUCING THE SAME UNDER PRESSURE INTOSAID UPPER HOT AIR CHAMBER AND FORCING ALL OF THE SAME OUTWARDLY THROUGHSAID INNER AND OUTER WALL STRUCTURES AND ADAPTED TO PASS SUCH AIRTHROUGH A COLUMN OF GRAIN TO THE EXTERIOR OF SAID SHAFT, (E) SAID AIRHEATING MEANS HAVING AN AIR INLET MEANS CONNECTED IN DIRECT AIR-FLOWCOMMUNICATION WITH THE FREE ATMOSPHERE SO AS TO RECEIVE AIR THEREFROMWITHOUT BEING DRAWN THROUGH THE SAID PERFORATED INNER AND OUTER WALLS,(F) SAID LOWER COOL AIR CHAMBER HAVING MEANS FOR SUBSTANTIALLY CLOSINGOFF ITS LOWER END TO PREVENT THE FREE ESCAPE OF AIR THERETHROUGH, (G)MEANS DISPOSED ENTIRELY WITHIN THE VERTICAL CONFINES OF SAID INNER WALLSTRUCTURE FOR CREATING PRESSURE UPON COOL AIR AND INTRODUCING THE SAMEINTO SAID LOWER COOL AIR CHAMBER AND FORCING THE SAME OUTWARDLY THROUGHSAID INNER AND OUTER WALL STRUCTURES AND ADAPTED TO PASS SUCH AIRTHROUGH A COLUMN OF GRAIN THEREBETWEN TO THE EXTERIOR OF SAID SHAFT, (H)SAID SHAFT HAVING AN OPEN BOTTOM AND SAID AIR HEATING MEANS BEINGCOMPRISED OF A BURNER EXTENDING UPWARDLY WITHIN SAID SHAFT WITH ITS AIRINLET MEANS CONNECTED INDIRECT AIR-FLOW COMMUNICATING RELATION WITH THEFREE ATMOSPHERE THROUGH SAID OPEN BOTTOM.